Don’t remap operators in DeclNameRef to identifiers

Fixes #833
Resolves rdar://100319818

Author: ahoppen

Sources/SwiftParser/Names.swift

@@ -57,7 +57,7 @@ extension Parser {
     if self.at(.identifier) || self.at(any: [.selfKeyword, .capitalSelfKeyword]) {
       ident = self.expectIdentifierWithoutRecovery()
     } else if flags.contains(.operators), let (_, _) = self.at(anyIn: Operator.self) {
-      ident = self.consumeAnyToken(remapping: .identifier)
+      ident = self.consumeAnyToken(remapping: .unspacedBinaryOperator)
     } else if flags.contains(.keywords) && self.currentToken.tokenKind.isKeyword {
       ident = self.consumeAnyToken(remapping: .identifier)
     } else {

Tests/SwiftParserTest/Assertions.swift

@@ -177,6 +177,7 @@ func AssertDiagnostic<T: SyntaxProtocol>(
 func AssertParse(
   _ markedSource: String,
   substructure expectedSubstructure: Syntax? = nil,
+  substructureAfterMarker: String = "START",
   diagnostics expectedDiagnostics: [DiagnosticSpec] = [],
   fixedSource expectedFixedSource: String? = nil,
   file: StaticString = #file,
@@ -185,6 +186,7 @@ func AssertParse(
   return AssertParse(markedSource,
                      { $0.parseSourceFile() },
                      substructure: expectedSubstructure,
+                     substructureAfterMarker: substructureAfterMarker,
                      diagnostics: expectedDiagnostics,
                      fixedSource: expectedFixedSource,
                      file: file,

Tests/SwiftParserTest/Expressions.swift

@@ -577,4 +577,12 @@ final class ExpressionTests: XCTestCase {
       _ = ##""" foo # "# "##
       """###)
   }
+
+  func testOperatorReference() {
+    AssertParse(
+      "reduce(0, #^PLUS^#+)",
+      substructure: Syntax(TokenSyntax.unspacedBinaryOperator("+")),
+      substructureAfterMarker: "PLUS"
+    )
+  }
 }